THOMSON AND MACKINNON — STOLON IFEE A, ETC. 1G9 



This strange form presents considerable difficulty. It shows certain points of 

 resemblance with the genera Sarcodictyon, Forbes, and CallipodUnn, Verrill, but, as 

 Kiikerithal has recently pointed out (Alcyonacea : Wissenschaf'tliche Ergebnisse der 

 deutschen Tiefsee-Expedition, 1906), these genera, together with a number of others are 

 better referred to Sympoditcm. Accepting, then, Kiikenthal's definition of the genus 

 Sj/mpodium as having "the polyps comi^letely retractile into the basal membrane," Ave 

 have described these specimens as a new species of that wide genus. 



Locality. Salomon, 120-150 fms. 



Genus CLAVULAIUA, Q. & G. emend. Kiikth. 



3. Clavularia scintillans, sj). n. (Plate 12. fig. 3; Plate 13. fig. 2.) 



This interesting form would be ranked as a Sympodium according to the older 

 classifications. If, however, we accept Kiikenthal's definition of Si/vipodium as having 

 the polyps completely retractile within the connecting membrane, then this species 

 must find its place in the emended genus Clavularia, with " the polyp-body divided into 

 a lower, calyx-like, thick-walled portion, and an upper, retractile, thin-walled portion, 

 bearing the tentacles." 



The colonies form encrusting, brownish-grey, india-rubber-like expansions on lumps 

 of coral. Erom a membranous base rise numerous richly spiculated calyces supporting 

 the upper non-retracted portions of the polyp. The average total height is about 5 mm. 

 Eor the most part they are so closely placed as to be almost touching, but here and 

 there intervening spaces of 1-3 mm. occur. 



The tentacles are short (1-15 mm.), plump, and strongly incurved. Erequently one 

 tentacle is placed nearer the centre of the oral disc than its fellows, and bends com- 

 pletely over the mouth-oiiening. Each tentacle has two rows of very short pinnules on 

 each side. There are from 6 to 8 in a row, and, in the retracted state, those of adjacent 

 rows seem to alternate. In a fully expanded tentacle there is possibly only one row. 

 Small, obviously young, polyps occur here and there among the others, with their 

 tentacles merely suggested by a circle of warts. 



Below the tentacles the body of the polyp is in many cases markedly swollen. Such 

 polyps were found to contain numerous reproductive bodies. 



The " spiculature " is very characteristic. Over the whole surface of the coenenchynui 

 and polyps there are numerous small rods, not unlike rice-grains, and apparently of a 

 yellowish colour. The spaces between these are filled up by minute whitish discs, which 

 give a scintillating appearance to the surface as seen through a lens. On the poly2)s 

 the rods tend to take a longitudinal direction, but, on the whole, their arrangement is 

 very irregular; they extend up on to the tentacles, but are not found on the oral side 

 nor on the pinnules, where there are discs only. 



Under the microscope the " rice-grains " are seen to be blimt or truncated rods, of a 

 dirty grey colour, with a minutely rough surface ('323 X '05 mm., '187 X '051 mm., 

 •102x017 mm.). The white discs appear as minute oval bodies like blood-corpuscles, 



